Method and mold for manufacturing telephone jacks



Get; 20, 1925. I

M. B. RICHTER IETHOD AND HOLD F08 MANUFACTURING TELEPBQNE JACKS Filed "arch 6. 1923 2 Sheets-Sheet 2 Patentedoct. 20', 1925;.

' and bushes.

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UNIT D STATES To allwkomitmayconce'm:

Be it-known that I, Momma Baurmzan RICHTER, a subject of the King of Denmark, residingl at Amaliegade 7, Copenhagen, Denave invented "new and useful Improvements Relating to the Methods and Molds for Manufacturing Telephone Jacks; and-I do hereby declare the following to be a full, clear, and exact description of the same.

The present invention relates to spring jacks or jack panels to be used in telephone stations and articularly to a method of producing 'ac s in such a manner that the contact bus es for receiving the connecting plugs are very firmly secured and get exactly uniform and cylindrical contact surfaces, so that the plugs fit smoothly and the' life of the jacks is increased.

A'further object of the invention is to secure the contact sprin ate. with the connection plugs simultaneously with and in amanner'siniilar to thefastening of the bushes so as to obtain predetermined relative According to the present invention in manufacturing the jack the bushes are placed each upon an internal cylindrical gauge of the required diameter, these gauges being arranged in a series in a suitable mold, and insulating material in a plasticvcondition is then pressed around the bushes to force their inner surfaces snugly against the cylindrical surfaces of the gau es and thereby form an insulating stri in which the bushes are rigidly secured a or the hardening of the insulating mass. The insulating -rear strip may conveniently be pressed simultaneously with the front strip, thecontact springs being for this purpose suitably arranged and supported within -.the mold.

As an insulating material to be used for this purpose cellon (acetyl cellulose) has roved to be well suited. However, other insulating substances may. also be used, and I- do not wish to'limit myself to the employment of any particular nsulating material. The bushes may comprise complete tubes -or the metal strips or so-called test springs for connecting theccontact bushes 'withjt 'e rear strip of the jack may made integral with the bushesby stamping out of sheet 'metal and the part of the stamped material adapted to form thebush is then bent around a cylindrical gauge to form a split-bush.

adapted to co-oper positions of said springs serte PATENT OFFICE. steam rayrnazaa orcormmaoiin, nmiusam I ammo!) mi) roan roa momorunme rnarkon uczs. Y

Application fled until a, ma- Serial Io. season.

The bushes may conveniently provided with one camera small p'r'o1 ections, perfo- The invention is applicable to two-con ductor jacks as well as to three or multiconductor jacks. v

' An embodiment of a mold for producing a-thr'ee-conductor 'ack is by we of exam-' ple shown on the rawing, in w ich' Fi ure 1 is vertical cross-section through a mo d with bushes and sprin s positioned therein, the dies and the ins ating strips being also shown in this figure.

Figure 2 is a fragmental view of the mold. seen from below, before pressing, a rtion of the lower part of the mold being. roken away in order to show the spin k 1 Figure 3.is a vertical lon 'tu nal sectionthrough one end of the 'mol -Figure 4 is a perspective view of; a bush with integral spring.

The mold shown on the drawing consists of a lower member 1 and-an upper L-shaped -member 2,-one flange of the latter consisting down inthe cavities. 9 indicates the con-- tact bushes with test s rings 10. As vexplained. aboveneach bus is placed upon a gauge 4. Contact s rings 11 and 11" adapt-' 1 ribs-13 and'lt extending downward from the u per member 2.- The springs 10 are in' into recesses 12 formed in the lower ed es of the ribs13and 14..

en'the mold is tobe made ready for the pressing operation it is turned through 1- 80-- with the bottom face upwards,

nov L the lower member 1 is removed, it being understoodthat the dies 7 and 8 are not yet i inserted into the cavities.

are then inserted through the bores above The, gauges 4 mentioned, the contact springs are inserted into the said -slots,'-and the bushes 9 are placed upon the gauges, whereupon a 'by forcing- 'their outer (foremost) ends downwards from the upper mold member tightly against the vertical surface 18 of."

the reinforcement 3; In this way the fore-' most ends of the bushes are brought into exact alignment. Thecontact springs 11 and 11 are prevented from displacement lengthwise and maintained in accurate alignment by small pins 19 projecting 2 and engaging the 'hooked inner. ends of the springs as' clearly shown in Fig. 2. It will be understood from the foregoingthat the elements 15'19 constitute a means for ensuring a predetermined distance between the foremost end of each contact bush andthe contact points 20 of the correspond-ing contact springs 11 or 11 and also for ensuring exact, alignment of the various bushes and springs However, other suitable means may beused for the same purpose. 'The wire 15 may" for instance be replaced by small pins individual toeach gauge. 4 i

The space for pressin the front insulating strip of the jack is Eounded at one side by the surface v 18 and at the other side, partly by a rib 22 projecting fromthe upper member 2 and provided with a series of semi-circular grooves, and partly by a similar rib 21 on the lower member 1. When the mold member 1 is placed in position. the opposed semi-circular grooves in the ribs 21 and 22 form together circular holes through which the bushes 9 pass.

When the'mold has been prepared as far as described, the lower member 1 is secured upon the upper member 2 by suitable means, not shown on the drawing, and the mold is again turned into its normal position, whereupon a suitable insulating material is filled in predetermined amount into the cavities 5 and 6, and the dies 7 and 8 are inserted into the mold. The mold is then heated to such a temperature, for example 150v (1., that theinsulating material becomes plastic. In this condition the insulating mass is pressed by means of the pressing dies 7 and 8 and a pressure distributing lever member 32 at -a' suitablepressure which may for example be about 80 or 90.kilos per s cm. The lever 32 may for example be acte upon by pneumatically operated. plunger 33. When the pressing ends are closed and the pressin operation has lasted sometime the moldis cooled, but the-pressing is continued until the mold is hand-warm and the insulating mass is completely hardened, whereupon the mold is separated and the an es are-removed. B this method t e ushes are pressed, intimately against the cylindricalsurfaces of the gauges, and the bushes and 'the springs are rigidly embedded in the insulatin strips 23 and 24 respectively formedeby this pressing operation. As shown in Figure 2 the bushes may be provided in their outer surface with small depressions. 34 -into which the insulating material is pressed during .the pressing operation.

- In order that the two insulating stripsmay be subjected to the re uired pressure per unit of area, which may e different for the two strips, the pressure is applied to the dies 7 and 8 by means of the said lever member 32, which is acted upon at a point A so positioned between the points B and .C of engagement of the lever member with the dies 7 and 8 that the lever arms I) and 0 stand in the required ratio to each other.

Through the upper -member 2 of the mold are bored two channels 25 and 26 communicating at their inner ends with the cavities 5 and 6 respectively and also communicating with vertical channels 27 and The connection between each horizontal channel and the corresponding vertical channel is controlled .by means of a needle valve 29 formed on a screw 30 provided with a head 31. During the first part of the pressing operation the communication from the interior of the mold to the outer atmosphere is kept open through the channels 25, 27 and 26, 28, so that a small part of the insulating mass is allowed to flow out through these channels until the dies during their downward movement reach a certain index, whereupon the needle valves I is continued.

If no insulating mass ows out through the channels when the dies have reached a certain point of. the downward travel it is hereby indicatedthat there is not suflicient insulating mass in the mold, and in this case more material must be added.

If bushes without slots are used when carrying out the method accordin 'to the invention the cylindrical gauges wil mainlyserve to maintain the original shape of the bushes, so that the latter are not deformed during the pressing operation.

Figure 4 shows an integral spring and split bush, the latter being' provided with small 1 for the purpose exp aine I (perforations 35 above.

Having thus fully described my invention I claim as new and desire to secure by Let ters Patent:

1. method of producing telephone jacks consisting, in placingl cylindrical bushes, adapted to receive connecting plugs, upon individual cylindrical steel gauges arranged in series m a suitable'mold, pressing insulating material of the condensation type in plast c condition, around the bushes at a substantial pressure sufliciently high to force the inner surface of the, bushes into intimateeontact with said gauges, allowing saidinsulating material to become hardenedwhile still maintaining said pressure, and

'removin said gauges after thehardening of the insu ating material to thereby form an insulating strip in which the bushes, properly. u ed, are embedded; v 2. nt e manufacture of tele hone jacks a method of producing an ins atin having cylindrical sing e-part contact ushes secured therein in almement, consisting in pressing insulatin material contaim'ng acetyl cellulose as a main constituent. in a plastic condition and at a. pressure of about 80-90 kilos per square centimeter and at a tem-- perature of about 150 C. around'said bushes whilethey are held-individually upon cyl1n-- drical gauges, to tightly press t e bushes into intimate contact with said gauges, allowing said insulating material to cool and harden while still maintaining said pressure,

and then releasing the pressure and with drawing the gauges. from the bushes.-

3.- A method of'producing jacks for telephone-stations consisting in arranging cylinrical gauges of equal diameters m a series in a mold, placingcontaet bushes for receiving the connectingplugseach upon a such gauge, inserting contact springs in said mold in a mold, plac1ng v co-acting with said plugs in the same. so.

. in plastic condition around said springs by means of two difierent dies, both,

lever acted upon at a point in correct positions relative to. said bushes and pressing insulating material'around said ,bushesand sprin s to'thereby form an insulating strip 1n w ich the bushes are, embedded and another insulating strip in which said springs are embedded. I

4. A method of producing jacks for telephone stations consisting in placing contact ushes for receiving the connecting plugs upon cylindrical-gauges arranged in a series contact springs for mold, and pressing insulatin 4 material operated by a single pressure distributing lying between the points of engagement of t e ever with strip 7 fitting closely around. the bushes.

gauges, means for accommodating contact springs within the mold, so that they extend through the other of said cavities and pressing means for-pressing insulating material contained within said cavities around said bushes and sp -6. A steel mold for producing the front insulating strip of a telephone jack, comprising a series of parallel cylindrical holes for accommodating a series of spaced cylindrical gau es respectively adapted to carry I contact bus es thereon, and means for bring- ,the outer ends of the contact bushes when placed upon said gauges into exact alignment.

comprising an up er L-shaped mold member having two para el vertical cavities in its horizontal part for receiving insulatin material and dies, and having a series 0 parallel horizontal-holes in its vertical part, said holes being perpendicular to said cavities and adapted to accommodate cylindrical gauges, two dies adapted to fit said cavities- 7 A mold for producing telephone jacks,-

respectively and a lower mold member abutting the inner surface of the vertical part of the upper mold member and the lowermost side of the horizontal part of the same and adapted to close said cavities at the bottom thereof, said Sl pper and lower mold members having oppo semi-circular grooves at that cavity nearest to the vertical part of the u per mold member and opposite tothe and holes, so that when the said mold members are assembled, after auges have been insorted through said ho es, and contact bushes laced upon the gauges, the said semicircuushes and argrooves form togethercircular apertures In testimony 'whereof- I have Iaflixed ature.

ORTEN BALTHA ZAR 

